Telephone-exchange system



Jan. 20s v J. B. RETAI-LACK TELEPHONE EXCHANGE SYSTEM Filed Ngv. 21',1925 s sheets-sheet 1 Jan. 20. 1925.

1,523,447 J. B. RETALLACK TELEPHONE EXCHANGE SYSTEM Filed Nov. 21. 1925ys sheets-sheet 2 Lema, 1245 UMS 223 Jan, 2o. l1925.

IJ'HU J. B. RETALLACK TELEPHONE EXCHANGE SYSTEM Filed Nov. 2l, 1925 3Sheets-Sheet 3 Patented Jan. 20, 1925.

el i@ F l JOHN B. RETALLACK, OF EAST ORANGE, NEW JERSEY, ASSIGNOB T0'WESTERN ELEC- TRIO' COMPANY, INCORPORATED, OF NEW' YORK, N. Y., A.CORPORATION OE NEVJ YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed November To all whom t may concern:

Be it known that I, JOHN B. Rn'inLLAoir, a citizen oi" the United Statesof America, residing at East Grange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements inleleplione-lilxchange Systems, of which the following is a full, clear,concise, and exact description.

The present invention relates to telephone systems, and particularly, tosystems employing automatic switches for the establishment ciconnections.

In telephone systems where connections are established automatically, itis particularly necessary that all the apparatus be kept in the bestpossible adjustment at all times. rl`his is true of the relays employedas well as of the switches themselves. In a manual system the testing ofrelays is a comparatively simple matter, but in machine switchingsystems, the adjusting of the apparatus, to bring it into such acondition that the desired relays may be tested, is a problem in itself.

In a system of the well-known power driven type suoli as is disclosed inU. S. Patent 1,504,261 granted to E. Il. Mills, August 12, 1924, inorder to test the so-called supervisory relays, it is necessary toposition the sequence switch which controls the operation of thesecondary or district selector in a deiinite position. In the case ofsuch selectors which serve subscribers who are charged on a` tlat ratebasis, the connection 0I" a dial to the selector and the positioning ot'that selector is not very diliicult. However, in t-lie case of selectorsserving subscribers lines equipped with coin boxes, the connection isnot completed and the supervisory relay connected into the circuit untilafter a coin has been deposited.

It is, therefore, an object of the present invention to provide simpleand eiicient means, in a testing arrangement for such a selector, tosimulate the action of a coin 1for the purpose of advancing the districtselector sequence switch into the desired position. A feature of theinvention lies in the provision of a. relay of the correct resistance toimita-te the coin box polarized relay and coin to advance the districtselector sequence switch to talking position.

A further feature of the invention lies in means for operativelyconnecting said 21, i923. seriai No. 676,023.

relay to the. test circuit under the control of an operator.

Another feature of the invention lies in means for releasing the coinsimulating apparatus by means of the coin collect or coin refund currentsupplied through the selector under test.

A still further feature oi the invention lies in the provision of' asignal which is displayed when tlie attendant operates the coinsimulating means and remains displayed until said means is released.

These and other features of the invention will be more clearlyunderstood from a consideration oi? the following description inconnection with the drawings and the appended claims.

This invention has been embodied in a disclosure like that shown in theabove mentioned patent to IC. H. Mills. In fact, in order to simplifythe drawings and description, two ligui'es of the drawing arepractically exact copies of two iigures of the Mills patent. In thedrawings, Fig. 1 shows a. test line embodying the present invention,Fig. 2 shows a district selector and Fig. a portion of a sender. Fig. lshows the manner in which Figs. 1 to 3 are to be arranged. F 2 differsfrom Fig. 2 oi' the Mills patent only in the addition of jack 290. Thevarious parts of the drawing bear the same numbers as the similar partsof the Mills drawing. F ig. 3 dilters from Fig. 12 ot' the Mills patentonly in the addition ot relays 6117, 719, G30, 626, and 1302 with theirassociated contacts and conductors. These relays pei-form the samefunctions as the correspondingly numbered relays in the Mills patent.Since the Mills patent describes iii detail the operation of the systemas a whole, reference is made to that patent for the portions of theoperation not completely traced in the present application.

For the purpose of testing district selectors a test line 100 isprovided which is equipped with a dial 102 for causing the districtselector to be positioned and with a pair of plugs 103 and 10d forconnecting the district selector to the relay test box 101,

The trunk conductors terminating in district selector switch 250 appearin multiple in the banks olf a plurality oia line switches and also injack 9.90 which may be mounted in any convenient position.

"When a district selector is to be tested,

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plug 103 is inserted in jack 290 and key 105 is operated. This key 105is a locking key and remains operated until released. The insertion ofthe plug in the jack immediately grounds 'conductor 291, thus renderingthe district Iselector non-selectable. As soon as the key 105 isoperated a circuit is cornpleted from ground, resistance 106, uppercontact ot' key 105, conductor 107, sleeve of plug 103, sleeve of jack290, lower right contact of sequence switch cam 203, lett normal contactot' relay 227, left winding ot sleeve relay 226 to battery in whichcircuit relay 22,6 operates.

Following the energization ot relay 226, sequencev switch 200 isadyanced into position 2 and a sender is associated withthe districtselector. The operator then manipulates his dial to set up aregistration on the sender corresponding to a number which may be onereserved tor such tests. 'The sender is now operated andthe districtselector positioned. Then the district selector has been positioned,sequence switch 200 is in position 9'. ln this position relay 261 isenergized from ground in' the sender and in4 energizing operates relay228. which in turn, advances the sequence switch to position 10, inwhich 'position the sequence switch remains during subsequentselections. VIn the meantime, monitoring time measure switch M, shown inFig. 3', has been' operated, due to the voperation of relay 626. Whenthe time measure switch lic/l'. passes through positions 9 and 1'0,'relay 1200 is operated. Since relays 1209 and 1216 have already beenoperated, a circuit is now completed to testwhether a coin has beendeposited. YIn the test line 100 the operation of key 109 represents thedeposit oi-a coin in a coin looXand closes a circuit for relay 110extending :from battery, winding of that relay, `closed contacts oitkey109 to yround at thev ba'ck Contact of relay 111. Relay 110 operates andlocks through its inner right iront 'contact direct to the ground on thehack contact of relay 111, Relay 110 also closes an obvious circuit Jforlamp 112 which indicates Vthat the coin deposit Asimulating apparatushas been operated.' At its outer right *front contact, relay 110connects ground through the winding of relay 111 and the upper contactot key 108 to the tip of plug 103' and thence to the tip conductor ofthedistrict selector. At its inner left front contact, relay 110 connectsground to the sleeve ot plug` 103 to hold the sleeve relay operatedafter the key 105 has been released'. Key 109 may he operated eitherbelor'ethe operation of the dial 102er iinmeiliat'ely thereafter. Thepreviously mentioned test circuit eX- tends 'from source 1260 otnegative current through the left front contact of relay 1229,

the inner right back contact of relay 1212, the outer right back contactof relay 1215, the lett windings of ditlerential relays 1214 and 1231,bank terminals Nos. 9, 10 and 11 to which wiper 1206 has access, wiper1206, the outer t'ront right contact of relay 1200, the outer right backcontact ot relay 1201, conductor 1202, left front contact of relay 630,conductor 636, wiper 232 of the sender finder SF, outer left'lirontcontact of relay 230, conductor 233, lower left contact ot cam 212, t'ipo'il jack 290, tip of plug 103, upper normalk contact of key 108, Vlowerclosed contact ot' key 105 through the dial 102, lower normal contacto'tkey 108, ring of plug 103, ring ot jack 290,-lower left contact olcani 213, conductor 23H5, inner lett front contact of relay 230, wiper266, right Jiront contact ot relay '630, outer left back contact ofl'relay 1201, outer leftfront contact ot' relay 1200, wip'er'1233 and theninth, tenth and el'eyenth cont-acts to which it has access 'through theright windingsnot relays 1231 and 1214, inner lett back contact ot relay1215, to ground at the VVouter right Contact of relay 1205. Relays 12141and1231 being` differentially and marginally V"wound do not energize inthis circuit.' loweyer,

it at this time key 109 hasbeen closed `Aand relay 1 11 connectedV to-the tip conductor,A an effective energizing circuit for relay 12111 isestablished, which is the saine as that 'previously traced as tar as thetip of 'plug 103 and upper contact of relay 108, and then extendsthroughthe winding of`1elayr111 to ground at the frontcontact of relay 110.Relay 1214 renergizes in series with the winding' ot relay 111, butrelay 1231'being margin ally wound doesnot 'energize and ifelay 111does` not receivesutlicient current through the windings ofrelays'121lluand 1231 to energize at this time. The operation ofrelay1j214" opens thev locking circuit of relay L120,95, releasing'relai 1216 which in turn opens the circuit of relay'647 and.

permits the completion ot' final units' selection as disclosed intheaboveV referred to Patent 1,504,261 to E. H. Mills. Relay 6417 serves toopen the `fundamental circuit through stepping relayv 719 et vthe senderwhen theV sender in position to control final units selection andprevents the completion ot a connection until a coin has been deposited.or, in this casefuntil Akeyv109 is closed. Y i Y V On the completion oicthe selecting operations, the current through relay 261, at whose vtrentcontactrelay 228 has been held energized, is reduced so that relay 261releases, in turnreleasing relay 22S which advances sequence switch 200into position 11. In position 11 a new Afundamental'circuit isclosedt'or controlling the advance ot `the sequence switch into thedesired talking `position, after which the sender is released.

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lVhen the district selector has been positioned in the talking positioncorresponding to the registration set up on the sender, supervisoryrelay '3-1 is connected through the upper right Contact 01" cani 213 andthe lower lett winding of repeating coil 265 to battery. Plug 10st maynow be inserted in relay test box 101, key 108 operated, and any desiredtest inade upon relay 234. rl'his test box may, for example, be ot thetype set forth in U. S. Patent 1,236,491 to B. l-l. Skinner, patentedAugust 141, 1917. The circuit of relay 231 may be traced in part tronibattery, lower lett winding ol' repeating coil 265, upper right contactot' cain 213, winding of relay 23-1, ring contacts oit jack L90 and plug103, lower alternate contacts otl key 108, ring contacts ot plug 104:and the jack oli test box 101, through the apparatus and circuits ol thetest box, and returning over the tip contacts oit the test box jack andplug 10st, upper alternate contacts ot key 103, tip contacts of plug 103and liack 290, lower right contact ot cani 212 to ground through theupper lett winding ot repeating coil 265.

1When these tests have been completed, keys 10S and 105 are released,the release ot key 105 simulating the release ot' the connection by thehanging up of the calling subscribers receiver. Supervisory relaydeenergizes opening the holding circuit ot' relay 227 and that relaydeenergizes to advance sequence 'switch 200 into position 16. Therelease ot' relay 227 opens one locking circuit of relay 226 but thatrelay is rnaintained energized by way of the lower left contact ot cani203 and the sleeves of jack 290 and plug 103, the inner left contact otrelay 110 to ground through resistance 106. 1n position 16 relay 228 isenergized and advances the sequence switch into position 17. ln position17 a sender is aga-in associated vith the district selector 250 and theoperation of the inonitor time measuring switch M again initiated by theoperation ot relay 626. lllhen switch M reaches position 5 relays 1212,1215, 1229 and 1200 have been operated and the circuit is closed forapplying coin collection current :troni the source 1261 ot positivecurrent through the inner right contact of relay 1229, winding of relay12%3, inner left itront contact ot' coin collection rela-y 1212, outerright front contact ot relay 1215,` thence in parallel through bankterminals 124:8 and 1249, wipers 1206 and 1233, outer right frontcontact and outer lett front contact of relay 1200, outer right backcontact and outer left back Contact ot relay 1201, thence overconductors 1202 and 1203 and over the circuit previously traced to thetip and ring contacts of plug 103 and to ground through the winding otrelay 111. Current now flowing through relay 111 is sutlicient tooperate that relay. The operation ot' relay 111 opens the lockingcircuit ot relay 110 and that relay deenergizes extinguishing lamp 112and removing ground at its contact from the sleeve ot plug 103 and jack290. As long as coin collection current liows, relay 110 remains lockedat its front contact but releases when the current ceases to flow. 'lheremoval of ground from the sleeve ot' plug 103 permits relay 226 todeenergize, disconnecting the sender and releasing relay 626 to restoreswitch M and the rest of the sender. rl`he deeneigization of relay 226advances sequence switch 200 to position 1.8 in which position the.district selector switch is restored to normal, whe-reupon sequenceswitch 200 .is returned to position 1. Since tests have now beencoinpleted on selector 250, plug 103 will be removed troni jack 290 andinserted in the corresponding jack ot some other district selector. rlheremoval oitI plug 103 from jack 290 removes ground troni the holdinglead 291, making district selector' 250 again selectable to lineswitches.

lVhat is claimed is:

1. ln telephone exchange system, a trunk circuit, an auxiliary switch, arelay, means tor connecting said relay to said trunk circuit in certainpositions ot said auxiliary switchf, ineans tor arresting said auxiliaryswitch in a` position prior to the positions in which said relay isconnected to said trunk circuit, means normally controlled by thedeposit of a coin for disabling said arie :ing means, a test. line, andmeans in said test line tor simulating the deposit or' a coin to operatesaid disablii'ig ineans to bring about the connection ot said relay tosaid trunk circuit.

2. In a telephone exchange system, a trunk circuit, an auxiliary switch,a relay, means for connecting said relay to said trunk circuit incertain positions ot' said auxiliary switch, `means lior arresting saidauxiliary switch in a position prior to the positions in which saidrelay is connected to said trunk circuit, means nornially controlled bythe deposit ot' a coin for disabling said arresting means, a test line,and operator conlrolled means in said test line lior sinuilating thcdeposit oli a coin to operate said disabling ineans to bring about theconnection ot said relay to said trunk circuit.

3. ln a. telephone exchange system, a trunk circuit, an auxiliaryswitch. a relay, means `tor connecting said relay to said trunk circuitin certain positions ot said auxiliary switch, means to arresting saidauxiliary switch in a position prior to the positions in which saidrelayY is connected to said trunk circuit, ineans normally controlled bythe deposit of a coin for disabling said arresting means, a test line,and operator controlled means in said test line coinprising a key and arelay controlled thereby :tomsimulating the deposit` of a coin-to operateasaid disabling' means to bring about the connection oi saidi'irstanentioned relay to said `trunk circuit.

4.In Va telephone exchange system, a trunk'circuit, an auxiliary switch,a relay, means Jfor connecting said :relay to said trunk lcircuit incertain positions ot' said auxiliary switch, `means for arrestingl saidauxiliary switch vin a positioirprior to the positionsf in which saidrelay is connected'to saidtrunlt-` circuit, a circuit normally adaptedto beclosed to ground through a Icoiirior disabling-said ari estiirgmeans, a test line, and means in said test linefor closingpsaid circuitto ground to operate said disabling means to bring about the connectionot said .relay to said' trunk circuit.

5. In a telephone exchange system, a trunk cricuit, an auxiliary switch,a relay, means ttor connecting said relay to said trunk circuit incertain positions of said auxiliary switch, means for arresting saidauxiliary switch in a position prior to the positions in which saidrelay is connected to said trunk circuit, means normally controlled bythe deposit oi" a coin tor disabling said arresting means, a test line.operator controlled means in said test line comprisingl a key and arelay controlled thereby 'for simulating the deposit ot a coin tooperate said disabling` means to bring about they connection of saidfirst mentioned relay to said trunk circuit, a source of coin collectcurrent, and means for releasing said second mentioned relay invresponse to the application ot' said coin collect current to the trunkcircuit.

6. In a telephone exchange system, a trunk circuit, :an auxiliaryswitch,1a relay., means for connecting saidmelay to saidtrunltr circuit incertain positions of said auxiliary switch, imeans for arrestingsaidauxiliary switch -in a position priorto Athe.positions in which saidrelayis connectedto said trunk circuit, `means normally ycontrolled by.the deposit of a coin for disabling. saidarresting means, a test line,operator ycontrolledimeans in said' test line comprisinga key andarela-y controlled l'herebyiorsimulatingr the deposit oi a coin tooperate, saiddisabling ineansto bringz about;the connection ot' saidiii-st. mentionedrelay to trunk circuitua source of coin collectcurrent, means for releasingsaid secondnientioned relay` in response tolthe application of said Vcoirrcollect, currentV to the trunk circuit,anda .signaldisplayed as long ,as-.said Acoin simulatiiig-means isoperated.

'7. In a telephone exchange system, a trunk circuit, an auxiliaryswitch, .a relay, means 'for connecting said relay Vto said trunkcircuit in certain positions of said .auxiliary switch, meansforarrestingsaid auxiliary switclrin apcsition prior tothe vpositions inwhich said relay is connected to said trunk circuit, `means normally.controlled Yby the deposit of a coinor disablino' said arresting; means,a test line, atestbox, means lin said line forvsimulatingthe .depositof`a ,coin to operate said disabling- .ineansto bring` about the connectionof sa-idrelay tosaid trunk circuit. and meansin. saidatest linetorconnecting said trunk` circuit .to `said test box.

In Witness .whereof7 hereunto subscribe my name. this 19th dayv of.November, A. D,

' JOHN B. .RETALLACK-

